Radiological criteria for a mass lesion are:  Lateral view   PA view

Note in gross cut section a mass which is well demarcated from the adjacent normal lung. Malignant tumors have infiltrating edges while benign tumors are rounded and well circumscribed.

Mass density can be encountered in 

Comprehend the following:

How would you radiologically distinguish Blastomycosis from lung cancer?

How would you radiologically distinguish Hamartoma from lung cancer?

What is your differential of a mass with air bronchogram?

What do you understand by the term " no respect for anatomy" ?